The brush hairs should only be saturated with warm water. Avoid ruining your brush by soaking it instead.
Mix a small quantity of gentle shampoo about the size of a pea into your palm and work it into your hair. Roll the brush around like this until all of the bristles are coated with the cleanser.
Create a baby or clarifying shampoo cleaning solution. Add shampoo to a bowl or shallow dish of water. Avoid exact quantities, but use a 1:2 shampoo-to-water ratio. Your brush is good as long as the water covers its bristles.
DIY cleaners with oil-based items should contain oil. A 1 US tbsp (15 mL) of olive or coconut oil can break down oil-based foundations and concealers and clean makeup brushes.
Pull the brush between your fingers making a ring with your thumb and index finger. Gently press down on the brush to squeeze out any extra water and keep its shape.
Spread out on a towel and let them dry flat. Avoid causing hair loss by drying your brush in an upright position, as this might release the glue that attaches the bristles.